edu.nyu.jet.lisp

Class FeatureSet

java.lang.Object

edu.nyu.jet.lisp.FeatureSet

public class FeatureSet
extends Object

A FeatureSet provides a mapping from interned Strings to Objects. It is intended to provide an efficient implementation for small numbers of features.

Field Summary

Fields

Modifier and Type	Field and Description
protected Vector	features
protected Vector	values

Constructor Summary

Constructors

Constructor and Description
FeatureSet() Creates an empty FeatureSet.
FeatureSet(FeatureSet fs) creates a new FeatureSet with the same features and values as fs.
FeatureSet(StreamTokenizer tok, boolean allowVariables, char endChar) This constructor reads a feature set from StreamTokenizer tok.
FeatureSet(String feat1, Object val1) Creates a FeatureSet with one feature/value pair.
FeatureSet(String feat1, Object val1, String feat2, Object val2) Creates a FeatureSet with two feature/value pairs.
FeatureSet(String feat1, Object val1, String feat2, Object val2, String feat3, Object val3) Creates a FeatureSet with three feature/value pairs.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	containsFeature(String feat) Returns true if the FeatureSet has feature feat with some value, possibly null.
boolean	equals(FeatureSet fs) Returns true if the FeatureSet is equal to fs: whether the two FeatureSets have the same features with equal values.
boolean	equals(Object obj) Returns true if the FeatureSet is equal to fs: whether the two FeatureSets have the same features with equal values.
Object	get(String feat) Returns the value associated with feature feat.
Enumeration	keys() Returns an Enumeration over the features in the feature set.
void	prepareToMakeString(int nestingLimit) add an 'id' feature to all Annotations referenced by this FeatureSet.
void	put(String feat, Object val) Associates the specified value val with the feature feat.
void	putAll(FeatureSet fs) putAll adds all the feature/value pairs in FeatureSet fs
void	remove(String feat) Removes the value associated with feature feat.
int	size() returns the number of features in the FeatureSet.
boolean	subsetOf(FeatureSet fs) returns true if the FeatureSet is contained in fs: if every feature in the FeatureSet is present in fs with the same value.
FeatureSet	substitute(HashMap bindings) Returns a new feature set in which every value of the original feature set which is a variable has been replace by the binding of that variable in bindings.
String	toSGMLString() returns a string representation of the feature set, without enclosing braces, of the form feature1=value1 feature2=value2 ... which is suitable when the feature set is part of an annotation or SGML tag.
String	toSGMLString(int nestingLimit, boolean useIds, boolean quoteValues) returns a string representation of the feature set, without enclosing braces, of the form feature1=value1 feature2=value2 ... which is suitable when the feature set is part of an annotation or SGML tag.
String	toString() returns a printable form of the feature set, of the form [feature1=value1 feature2=value2 ...].
static FeatureSet	unify(FeatureSet a, FeatureSet b) If every feature which occurs in both FeatureSets a and b has the same value in both FeatureSets, returns a new FeatureSet with the union of the features; otherwise returns null.

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

features

protected Vector features

values

protected Vector values

Constructor Detail

FeatureSet

public FeatureSet()

Creates an empty FeatureSet.

FeatureSet

public FeatureSet(String feat1,
          Object val1)

Creates a FeatureSet with one feature/value pair.

FeatureSet

public FeatureSet(String feat1,
          Object val1,
          String feat2,
          Object val2)

Creates a FeatureSet with two feature/value pairs.

FeatureSet

public FeatureSet(String feat1,
          Object val1,
          String feat2,
          Object val2,
          String feat3,
          Object val3)

Creates a FeatureSet with three feature/value pairs.

FeatureSet

public FeatureSet(FeatureSet fs)

creates a new FeatureSet with the same features and values as fs.

FeatureSet

public FeatureSet(StreamTokenizer tok,
          boolean allowVariables,
          char endChar)
           throws IOException,
                  PatternSyntaxError

This constructor reads a feature set from StreamTokenizer tok. The input should have the general form
feature = value feature = value ... ]
where the value may be an integer, a symbol, or a string; if parameter allowVariables is true, the value may also be a variable. The FeatureSet ends in token endChar ("]" in the example above). Feature-value pairs may be optionally separated by commas. On entry, the first feature should be the next token to be read from tok (not the current token).

Throws:

IOException

PatternSyntaxError

Method Detail

put

public void put(String feat,
       Object val)

Associates the specified value val with the feature feat.

putAll

public void putAll(FeatureSet fs)

putAll adds all the feature/value pairs in FeatureSet fs

get

public Object get(String feat)

Returns the value associated with feature feat.

remove

public void remove(String feat)

Removes the value associated with feature feat.

containsFeature

public boolean containsFeature(String feat)

Returns true if the FeatureSet has feature feat with some value, possibly null.

subsetOf

public boolean subsetOf(FeatureSet fs)

returns true if the FeatureSet is contained in fs: if every feature in the FeatureSet is present in fs with the same value.

equals

public boolean equals(FeatureSet fs)

Returns true if the FeatureSet is equal to fs: whether the two FeatureSets have the same features with equal values.

equals

public boolean equals(Object obj)

Returns true if the FeatureSet is equal to fs: whether the two FeatureSets have the same features with equal values.

Overrides:

equals in class Object

keys

public Enumeration keys()

Returns an Enumeration over the features in the feature set.

size

public int size()

returns the number of features in the FeatureSet.

substitute

public FeatureSet substitute(HashMap bindings)

Returns a new feature set in which every value of the original feature set which is a variable has been replace by the binding of that variable in bindings.

unify

public static FeatureSet unify(FeatureSet a,
               FeatureSet b)

If every feature which occurs in both FeatureSets a and b has the same value in both FeatureSets, returns a new FeatureSet with the union of the features; otherwise returns null.

toString

public String toString()

returns a printable form of the feature set, of the form
[feature1=value1 feature2=value2 ...].
Inverse features, ending in "-1", are suppressed to avoid infinite loops.

Overrides:

toString in class Object

toSGMLString

public String toSGMLString()

returns a string representation of the feature set, without enclosing braces, of the form
feature1=value1 feature2=value2 ...
which is suitable when the feature set is part of an annotation or SGML tag. Inverse features, ending in "-1", are suppressed to avoid infinite loops.

toSGMLString

public String toSGMLString(int nestingLimit,
                  boolean useIds,
                  boolean quoteValues)

returns a string representation of the feature set, without enclosing braces, of the form
feature1=value1 feature2=value2 ...
which is suitable when the feature set is part of an annotation or SGML tag. Inverse features, ending in "-1", are suppressed to avoid infinite loops.

Parameters:

nestingLimit - limit of depth of nested Annotations which will be represented in the String.

useIds - if true, references to Annotations which are nested more deeply than 'nestingLimit' are rendered as '#nnn', where 'nnn' is the 'id' feature of the referenced Annotation; if false, these references are rendered as "..."

quoteValues - if true, values of features are enclosed in double quotes, as required by XML. Quotes inside quoted values are escaped (preceded by a backslash).

prepareToMakeString

public void prepareToMakeString(int nestingLimit)

add an 'id' feature to all Annotations referenced by this FeatureSet. This is invoked prior to converting this FeatureSet to a String, if annotation references are to be converted to '#nnn' form.